In recent years, more and more home electrical appliances have been network-enabled, and they are increasingly used in a way in which their communication apparatuses with the wireless local area network (LAN) function communicate with each other without through base stations.
For wireless LAN devices conforming to the IEEE 802.11 series standard, there are ad-hoc network specifics called the independent basic service set (IBSS) for directly connecting the devices. With an ad-hoc network, all communication apparatuses are in equal relationship, and typically, if communication parameters are correctly set, relevant communication apparatuses can be readily connected to each other.
One example method for limiting communications between communication apparatuses is the one by specifying an address, such as a MAC address, of a partner and filtering a received packet. For an infrastructure network between a wireless base station and a wireless child station, there is a mechanism in which a MAC address corresponding to a connection that should be denied is specified in a base station to limit a connection of a child station (see, for example, Patent Literatures 1 and 2).
A function of easily setting communication parameters between a wireless base station and a wireless child station (Wi-Fi protected setup (WPS)) is proposed by the Wi-Fi Alliance, which is the industry standard group (see, for example, Non Patent Literature 1).
When communication apparatuses having the wireless LAN function directly communicate with each other without through a wireless base station, an ad-hoc network is used in many cases. For an ad-hoc network, if communication parameters of communication apparatuses match with each other, they can communicate, so convenience is high. The communication parameters can be readily set by the use of the above-described WPS.
To prohibit a specific communication apparatus from participating in a network, for an infrastructure network, because communication is carried out through a base station, denial of connection, such as filtering setting using MAC addresses, can be set in the base station. However, for an ad-hoc network, communication is not carried out through a specific apparatus, such as a base station. Accordingly, denial of connection, such as filtering setting using MAC addresses, needs to be set for all communication apparatuses, so the operation is complicated.
Even when denial of connection is set in a base station, if communication parameters are set by communication apparatuses using a simple communication parameter setting technique, such as WPS, an apparatus that should not communicate may easily communicate.    Patent Literature 1: Japanese Patent Laid-Open No. 2003-204338    Patent Literature 2: Japanese Patent Laid-Open No. 2004-072682    Non Patent Literature 1: Wi-Fi CERTIFIED™) for Wi-Fi Protected Setup Easing the User Experience for Home and Small Office Wi-Fi® Networks, http://www.wifi.org/wp/wifi-protected-setup